Lymph node response rate is defined as the proportion of participants who achieve a ≥ 50% decrease from baseline in the sum of the products of the greatest perpendicular diameters (SPD) of index lesions.

This Phase 3, randomized, double-blind, placebo-controlled study is to evaluate the effect of idelalisib on the onset, magnitude, and duration of tumor control. Eligible patients will be randomized with a 1:1 ratio into 1 of the 2 treatment arms to receive either idelalisib or placebo. All subjects will be administered bendamustine and rituximab.